Multispectral Imaging (Fluorescence) is based on the acquisition of a series of images recorded at different wavelengths from 400-700 in bands of 5 nm with a system based on the use of a liquid crystal tunable filter coupled to an imaging detector. Reflectance Imaging is performed with illumination using white light, or alternatively, using UV-light source for the excitation of luminescence. A large cube of data (based on the superposition of images acquired at 65 different wavelengths) is compiled and this dataset can be analysed using advanced statistical methods.These methods allow an easy visualization of differences in an image (based, for example, on the presence of pigments with different reflectance properties) and can be used to highlight areas in a surface which exhibit similar fluorescence and reflectance properties. Generated maps can be related to areas containing the same pigment and binder mixtures, or can be used to highlight the presence of restoration or pentimenti.
D. COMELLI, G. VALENTINI, NEVIN A., FARINA A, L. TONIOLO, R. CUBEDDU (2008). A portable UV-fluorescence multispectral imaging system for the analysis of painted surfaces. REVIEW OF SCIENTIFIC INSTRUMENTS, vol. 79, p. 086112 (1)-086112 (3), ISSN: 0034-6748 D.
COMELLI, NEVIN A., VALENTINI G, OSTICIOLI I, CASTELLUCCI EM, TONIOLO L, GULOTTA D, GALLONE A, CUBEDDU R (2011). Imaging and analysis of a red lake pigment in wall paintings by Masolino da Panicale in Castiglione Olona. JOURNAL OF CULTURAL HERITAGE, vol. 12, p. 11-18, ISSN: 1296-2074, doi: 10.1016/j.culher.2010.06.003.